Hogie Roll, this is an experiment and so far is working fine but I know the numbers can improve quite a bit since everybody around is not an engineer but just handy man trying to be knowledgeable. Its amazing the lack of knowledge among the businesses doing repowers and conversions. I think I need to lower the engines several inches inn order to avoid cavitation.
https://cimg4.ibsrv.net/gimg/www.off...bc670515d8.jpg

Nice project, and it sure didn’t take long.

Hey hoggie roll, you say raise them, I thought lowering them since I get a bit of cavitation. What do you think? WOT is 54mph at 6000 rpm's.

This is really cool, if you are getting 1.6 mpg at 42 mph that is awesome. My 330 with 496's was at 1 mpg no matter what. you just picked up a ton of range... What is the plan for the engine compartment?

He may have thought the slower figures (42 mph) was WOT, I wasn't too sure but you've cleared that up now. :)
The figure of 54 mph @ 6,000 revs is pretty impressive. There might be more in it if you can get the revs up a little by playing with engine height and maybe props. Depends what you're looking for but I'd say you've done very well for a first run.

RR

Agree with RR. I'm impressed with the numbers you are at. 1.6 at 42 is very good. Great job.

Thats a pretty good WOT number, but the engines can spin faster.

Are the engines cavitating at WOT? Or just when accelerating?

Mine will cavitate if I go WOT from low speed. I just manage it with less throttle. But I still have great acceleration regardless of this. My boat is probably 2k lbs lighter though.

Did you trim them up a lot while testing? Like until it slowed down?

I’m forgetting this is a 280, not a 330. there should be something more speed in there.

im on the west side right now, but possibly heading over there is the next few days. I could stop by and check it out. Are you spinning out or in?

Picture above appears to be spinning out. Also I'd like to bring up that you are running 3 blades. We are rigging the contender out with the same engines in the upcoming weeks. Already have a set of merc revolutions here for them when engines arrive. The 4 blades would really help you on the hole shot.

Zuke props have a big diameter